Apparatus for heat exchanging



G. T. MOTT APPARATUS FOR HEAT EXCHANGING vr, IWA

May 13, 1930.

Filed Feb. 12, 1927 2 Sheets-Sheet l INVENTOR l ATTORNEY L-lul lll willllll.

May 13, 1930. G. r. MoTT v APPARATUS F013 HEAT EXGHANGING 2 Sheets-Sheet 2 Filed Feb. 12, 1927 ATTORNEY Patented May 13,1930

PATENT OFFICE GEORGE MOTT, PEARL RIVER, NEW YORK f APPARATUS FOR HEAT EXCHAN GIN G- Application filed Febrary-12, 19,27. Serial No. 167,684.

' a heat agent, shall be reduced to a minimum and the evils consequent upon such frictionalV resistance correspondingly obviated.

Another object of the invention is to make such a tube element capable of receiving at its entry port fluid in quantity suliicient to utilize thefull capacityof the tube element.

Other objects of the invention are to prvi de a tube element of the character described which shall be simple and economical in" construction; easily installed and conveniently accessible; whose parts may be easily removed and replaced or duplicated; and one of the parts of which shall bo adapted for cleaning part ofthe tube element proper. rllhese and other objects of the invention will be more fully set forth in the following description.

Inr the accompanaying drawings which are referred to hereinand form part hereof,

Fig. 1 is a longitudinal section of part of a heat exchanger in which is employed and shown tubes constructed in accordance with the invention and which form the heat transfer surfaces of the heat exchanger;

` Fig. 2 is a view in cross-section taken on the line 2 2 of Fig. 1, showing the relationship of the inner and outer tubes of Fig. 1 and the tube-supporting members;

Fig. 3 is an enlarged view, parts being broken away, in longitudinal section of an inner and outer tube shown in Fig. l and showing the same more in detail l Figt is a similar view taken on aplane at right angles to the plane of the section shown in Fig. 3; Y

Fig. is a longitudinal section of part of a tube element and shows the same arranged for a reverse flow of the heat agent used there m. e

Fig. 6 is a longitudinal-section of anend of an inner tube used in the device, showing ole- Y tails, and is also taken on a plane atright angles to the plane of the section shown in Y Fig. 3;

Fig. 7 is a view, partlyV in elevation and partly in cross-section, taken on the line 7-7 of Fig 6;

Fig 8 is a similar view taken on the line 8 8 4 of Fig 3; j

Fig. 9 is a perspective view showing in detail the retaining members shown in Fig.' l;

Fig. 10 is a sectional view of the endof a tube of the art, illustrating the flow of a stream-of liquid intothe tube; and

Fig. 11 is a lperspective view, parts being broken away, of an endofa tube constructed 1n accordance with-the invention and illustrating the flow of a stream of liquid into theV same.l c

Refering to the drawings in detail, there is illustrated therein a preferred embodiment of the invention as used in a heat exchanger n of the typey shown in my: co-pending application, Serial No. 127 ,039, filed August 4, 1926, and which need not be described in detail herein. Said heat exchanger consists generally of a vapor chamber 15 formed with a cylinder shell 16, having heads 19 and 20 and provided with-the usual vapor flow ports, not shown. At one end of said vapor chamber 15 and spaced apart therefrom so as to provide an air gap between them is arranged a container 26 divided by a partition wall 29 into receptacles 39 and 40 which are provided with inlet and outlet ports not shown. One of the heat agents, as for example, oil,

enters the receptacle 39 andV then the tubes said receptacle 6l. These tubes lead from 39 and,- passing through the receptacle'llO, project into the outer tubes 53'.. These latter tubes 5,3 lead from the receptacle 40 and, traversing the space between the container 26 and the vapor chamber-.15, project into the vapor chamber 15 through the head 19. The closed ends of the tubes 53 are freely supported on curved supportingzmembers 54?, see Fig. 9, preferably @est integrally with the head plate 20. Y As shown, these supporting members 54Ca are arc-shaped and arel employed, four to each tube end, with space between each two arcmembers. Further ref- -y erence will be made to these supporting members. The supported ends of the tubes 53 are sealed with plugs 55a, preferably screwed intothe ends of the tubes. It will be seen that the oil enteringthe tubes 61 will pass therefrom at their extreme inner ends into the outer tubes 53 and, abruptlychanging the Y direction of flow, pass throughv said outer 5 vapor in tubes 53 into the receptacle 40, absorbing in its passage the heat from the heat-containing the vapor chamber 15. It is with f these tubes and their associatedparts that standing of the present invention'.

i; tube. Also, the heat exchanger may be used so that thev heat-containingf agent flows i through the tubes while the heat-absorbing orifice, when used as thecapacity of` this tube element.

'the small agent is inthe chamber 15.jvr y y f Itis to be observed thata sharp-edged tube 'an entry port, will subject thev entering liquidV to jet contraction, and it is the contracted cross-sectional liquid area at this point, rather thanV the actual crosssectional areaof the tube which determines After passing the area ofcontraction, and because of frictional resistance which causes a slowing up of theliquid flow, aliquidV expansion 'occurs' which fillsthe entire tube but at a vvelocityincident tothe quantity which it possible to pass through the contracted area-- It will be obvious that'thisreduced flow imi- -plies a mechanicalcapacity lossof great relative dimensions, and Vparticularly in a heat exchanger where thermal eiiiciency demands a high velocity;

`Accordmg to one feature of the invention, therefore, an entry port is provided for the vtube through which the heat agent or liquid enters the tube element, which port shall be V capableof admitting liquid to the tube proper in volume equal to the' full capacity of the tube, `and which port preferably, vshall not involve any' change in the tube structure which wouldl'renderthe tube unfit for use with certain desirable associated parts.

In this connection it is to be noted that the f lowof liquid intoa tubeat a velocity sufficient to induce aV contracted areawith an adliacent expanded liquid area .will cause the liquid to form a closed annular space around diameter of the liquid column at the point of contraction and'that the con# stant drag by theflowingliquid Von the atoms ofairin theenclosed space will have a tendency to rarefy the air body and thus cause a partial vacuum. T he improved entry port, therefore, provides for filling this annular air space and presenting at this point of contraction a coherent, liquid body equal to t-he full capacity of the tube and maintaining this coherent, efficient flow throughout the tube element. As shown, see Figs. l, 3 and 6, the peripheral wall of the tube is formed with `a serratedV edge forming extending tongues r 63 with intervals of space between them, and the entering liquid stream is admitted to the tube at different intervals and entry planes aboutand between thetongues. There will yet be atendency to form the area of contractionat the lower edges or lowest entry point in the said serrated edge but in a reduced dimension. Flowing down the extendedtongues 63 of the tube end and at the point of contraction will be integral streams of liquid which will have previously met all frictional entryV demands upon'them, these streams alternating With voids 64 formed between and at the bases of the said extended tongues 63, see Fig. 11, and thus entering the operative portion of the tube at intervals. The immediate effect at these voids 64 is to draw theliquid ofthe two adjacent liquid streams from the tongues on both sides of the valleys in parallel, vertical, transverse, and diagonal streams into the voids and fill them andthus form an integral liquid body or column equalto the full capacity of the tube and maintaining this integral efficient fiow throughout. It will be seen that the lserrated edges' by increasing the length of flow line decrease proportionately the velocity of the immediate entry flow and thus cause a reduce tion in total frictional head and provide for Va full capacity stream. It will also be seen that an entry port formed as thus described will interpose no vobstacle to the use of any kdesired associated partsf with.` the tube. As

shown, .for instance, see Fig. 6, the gland 63a maybe used, the same fitting tightly over the stufiing 63h. And it isv pointed out that when the direction of the flow is reversed and the heat agent enters theouter tube 53 first and then flows from the tube53 into the inner tube 61, the entry port of the tub-e 53 may be fashionedas above described in. connection with the entry port of the tube 61, or as shown.' l

A defect common to the double tube elements of the art for heat exchanger service lies in the fact that, where the tubes are of equal cross-sectional area and of similar cross-sectional contour, the liquid in the outer tube is of so thin a-stream that the adhesion of theliquid to the peripheral walls of the not by the lack of space between the inn-er and Y outerftubeslbutfbynelicient outlining Qfithe saine. Both tubes being Similar ingcIOsssectional .c0nto,ur,'1,the, space -betiveen the finnerand outertubesniay fbefequaltoithe .space Within ,the inner; tube and lyet, as =Wi^ll ,be-seen, because of the l,sp-ace between ,the tubes fbeing defined by ,the y annular ring :f0r1ned`;b,y the outer tube a-round'fthe innertube, the compact stream of liquid issuing ffrom-the inner -tube'wilh when divertcdunto{the-outer tube, fbc; expanded into gthe --tlin stream above re- K fcrre-d to which will undulykadher'e'pto-the peripheral walls of :thesurrounding-tubes. 1 ,ilrccerding-ato "another featureof the f invenf contour as will proyidey enlarged spaces. It vill .be seenthatthelarge spaces 6,8,.thus pro,-

- v.stream issuing:

,i y1s ,rendered easier.

, theloiv is broken,

-= ing an even, continuons 4vided betvveenthe tubes ,on ,the fopposite `.ends of the `miner. l axis @,f .the inner rtube, prrW-ide .sexerally ,for easyfloxv of;the-1entireliqnid :frointhe i inner tube, yreduced adhesion of the liquidto .thesurreundingtube Wallsand;reduedfrictionalefect. Alsofbe- ,cause of ,Saidilarge ,spaces .6,8 `the labrupt `changeof-dfirectioii of the flew ofzthe gliquid -Furtllermcre lthe Lfric- :tional `resistance of the liquid :being reduced, Athe raising ef ,temperature icaused byasaid lfriction al Aresistance is )also @eliminated and with it the many and serious evils attendant ,thercen lt is` l,pointed out thatin ,constructions pf .the .artthe I.liquid passing ,from an .inner A-to the router ,tube I,makes lashort, ,sharp .turn vWith-the result thatthe even .centinuity ,of the speed ,diminished i by ,increased fricticnal resistance, and erosion of ,the outerk ,tube is promoted ,bythe centinual xsharp impacts of' 4the liquid 3aga-inst `Ysaid tube. Further to ,assist in maintain- ;iiovvcf the liquid stream, therefore, and :according -to another feature of the ,inventionadivergin'gfblocl Ior deflector 69 is provided in the outerutube 53 adjacent Fthe innerend ofthe inner tube 61,

' `see Figs; 3andd. 'llhisiblgock'or defiector-69 als arranged .innlace nzthe inner ftubefl in iam/suitable@manner Asfshovvn, itis fast- Nenediby rneansi'ofilugs Z0 extending, .one `on leach side, 4:from theeend of saidninnertube 61, ,and r:lifting-:intesuitable 4recesses, onel :in

median line,

`fing its speed 'and Without fofthetubes. fdiyerging Vblocks may `be .formed 'With :their curved faces ,site sides of or dejector v,deflecting faces.

rand curvature to v which ,are continuous vis afforded inthe diverging block or .v

each side oflsaid block. Angend 7 lof each lub 7 Ogis turned andifitsinto lanother-.suitable recess fin said :block andadditionallyfthegalug is fastenedto the block With a screvvV 72. 'The diverging block or deiector 69 kfits snugly into the outer tube 53 and is formed -vvith relatively sharp peripheral edges 73 made necessary by the requirements for a `smooth surface and a low resistance effect. Said blo'ckorv-deliectorGQ is formed vvithlan endV dishedfout or recessed lon each sideof a forming a sharp edge.;74, eX-Y tendingacross the end of thezbloc'k. 'f 011 each side of this sharp median edge 74; thegoppolsitelylcurved faces LZ6 and Nef-each recess :diverge from said medianedge in-such Inanne'r as to vprovideat everylpoi-nt (throughout eachentireface theexact angle of divergence -fera `'liquid of any given viscosity, and for theidiameter of any particular-turner diversion.V 'It Will be seen Jthat the `iliquid astreain, follovvingthese curved-first 'in one direction towards Vthe end Yofthe outer-tube :and then :swerving swiftly but gradually yin the freeversedirection will make the dcslcdfchange in lflovv Without impair-ingy `the even, ,con-

tinuousfflovv ofthe liquid and Without-.checke injuring the Walls It is to benoted alsothat these 't' 6, lWin variable form Aonoppothe recessed portion ofthe block theouter tubeffto -theinnertubefin the same vment .of speed. Ift vfisgpolnted 'outvthatV the block or deector 69 is so positioned/:Witheela'tionfto -theend of the :inneritubeil that' the full y,volume` of liquid will -bepermitted-fto `fflovv from `one -ftube to the if other normally -u-ninfluenced by the 'fritonalrresistancesto such .a cha-nge .of direction, this ibeing effected by `the ,posi-tion and `variable Vcurvature of the ItA is to vbe understoodthat the fdeflecting blocks will varysin lstructure 1 ,meet the requirements `for viscosities.

so that the `liquid mayflovv from v VAs has been stated, the ,blockior vdeiiecter e115 69 is formed With' relativelysharp edges 'on bothrsides and serve the-additional pur kpose of .tube cleaningVboth -When entering .the tube :and Iwhen ,removing forifrepairs yor other reasons. )The block ,isfurther formed `With a threaded orifice 7 8 so that a pipe or ,rodanayibeapplied 15er direct cleaning. It Will be noted also, see Fig. 3, that a space y79 outer Vtube between said deflector59l @11d the vsealing. plug v55a at the end, gif desired, orfsaid blockagrld plugrnay-be made Aintegral. e, fReferring vfto the supporting Amembers k54a -ffcrthegends ,ofthe tubes, itis tobe. llntedthat around the .outer limits Y aso i they are formed in segments to prevent the distortion `under high temperature incident vinto the other,

the outer tube andassociated with the innerV toarc members of greater dimension.

The vinvention in its broader aspects Vis not limited to the precise construction shown and described, nor to any particular construction by which the vsame may be carried into eiiect, as many changes may be made in the `end of the inner tube, said detlector being divided by a central sharp edge and-diverging therefrom-intofcurved recesses. y

' 2. A friction-reducing circulating unit for heat exchangers and the like including` in other tube at the angle of divergence for a liquidof a given viscosity and for the diamt even, continuous flow.

.wherebythe liquid tube and presenting to cluding in combination,

combination, ,inner and outer tubes and a removable deflector arranged in the outer tube, said de'lector presenting to the adjacent end of the inner tube asharp outer edge from whicliextend recesses to a median line,'the faces of said recesses being curved to provide for the liquid stream vflowing from thenner tube into the outer tube at the exact angle of-divergence for a liquid ot a givenviscosity and for anyfgiven diameter of diversion, will iiow from the inner tube into the outer tube in Van even, continuousflow. f t j i 3. A rictionfreducing circulating'unit for heat exchangers and the like including in combination, ninner and outer tubesrand a removable deector arranged in the outer the adjacentend of the inner tube a sharp outer edge from which extend recesses to a median line, the faces of said recesses being curved to provide for the liquid streamflow/ing from one tube into the eter of the diversion, whereby the liquid will flow from onevtube to the other tube in an 4. A friction-reducing circulating unit ininner and outer tubes, the inner tubes being substantially oblong in cross-sectional contour, and the outer tube being substantially circular in crosssectionalcontour, and the flow axes of said tubes being substantiallyparallel thruout the length of said inner tube.

5. A friction-reducing circulating unit including in combination, inner and outer tubes,fone of said tube being substantially oblong in crossisectionalcontour, and the other tube being substantiallycircular incross-sectional contour,

and the -fiow axes ot said tubes 1 of and between said tongues,

' ing into the other,

being substantially parallel thruout the length of one of said tubes.

6.'A friction-reducing circulating unit including in combination, an outer tube and an inner tube contracted on one diameter and expanded on the other, and the flow axes of said tubes being substantially parallel thruout the length of said inner tube.

7.A Inor for a friction-reducing circulating unit Jfor heat exchangers Hector presenting a face adapted to divert the flow of a liquid stream, the perimeter of said face-having a sharp edge.

8. In or for a friction-reducing circulating element Jfor heat exchangers and the like a deector presenting a the flow of a liquid stream, the perimeter of said face having a sharp edge and the face on the reverse of said deflector also having its perimeter formed with a sharp edge.

9. A friction-reducing circulating unit including in combination, an `outer tube, and and innertube, onev of said tubes being contracted on one diameter and expanded on the other, and the flow axes of said tubes being substantially parallel thruout the length of said inner tube.

10. A friction-reducing circulating unit for heat exchangers and the like including in combination, an outer tube, an inner tube, one of said tubes being contracted on one diameter and expanded on the other, and a delector arranged in said outer tube and associated with said inner tube, said deflector presenting curved acesto the fluid stream flowing from said inner tube.

11. A friction-reducing circulating unit `for heat exchangers and the like including in combination, a 'tube,.a removable plug arranged at one end thereof, and a removable deiiector arranged in said tube, whereby said plug can be removed to permit ready insertion or removal of saiddeflector into or from said tube.`

l2. A friction-reducing circulating unit for heat exchangers and thelike including in combination, a pair of tubes, one projecting into the other, the outer end of the inner tube being formed with extending arc-shaped tonguesand arc-shaped valleys atthe bases and a deflector arrangedin said outer tube and associated with said inner, tube, said deflector presenting curved faces to the fluid stream flowing from said inner tube whereby said stream will pass thru said unit in an even, continuous flow in volume equal to the Jfull capacity lof the tubes.

13. A `friction-reducing circulating unit for heat exchangers and the like including in combination, a pair of tubes, one projectan open end of one of said tubes being Jformed with extending arcshaped tongues and arc-shaped valleys at the bases of and between said tongues, and a deand the like a de- 80 tace adapted to divert Y Hector arranged in theouter of said tubes adjacent the inner end` ofthe inner tube, said delector presenting curved faces to the fluid stream flowing from said tube with the arc-shaped tongues to the other tube, whereby said stream will pass thru said unit in an even, continuous flow iny volume equal to the full capacity o-f the tubes.

14. A friction-reducing circulating unit for heat exchangers `and the like including in combination, a pair of tubes, one projecting into the other, an open end of one of said tubes beingl formed with extending arcshaped tongues and arc-shaped valleys at the bases of and between said tongues, one of said tubes being contracted on one diameter and expanded on the other, and a deflector arranged in said outer tube and associated with said inner tube, said deiiector presenting curved faces to the fluid stream flowing from the tube with said arc-shaped tongues to the other tube, whereby said stream will pass thru said unit in an even continuous ow in volume equal to the full capacity of the tubes. In testimony whereof, I have aixed my signature hereto.

GEORGE T. MOTT. 

